Hammer type stapling machine



Sept. 29, 1953. w. R. BECKMAN Er AL 2,653,317

HAMMER TYPE STAPLING MACHINE Filed Sept. l, 1951 10 SheetsfV-Sheet 1@M4/M @g a1/Wan g5 Sept. 29, 1953 Aw. R. BECKMAN Er AL l 2,653,317

HAMMER TYPE STAPLING MACHINE Filed Sept. l, 1951 l0 Sheets-Sheet 2 Sept.29, 1953 R. vBI; :KMAN ET ALW. t2,653,317

HAMMER TYPE STAPLING MACHINE:Y

Sept- 29, 1953 w. R. BECKMAN m' AL 2,653,317

HAMMER TYPE'sTAPL1Nq MACHINE Zjg M7 @MJ v4/XML i575 w. R. BECKMAN Er AL2,653,317

HAMMER TYPE` STAPLING MACHINE sept. 29, 1953 10 Sheets-Sheet 5 FiledSept. l, 1951 Sept-'29, 1953 V w. R. BECKMAN Er A1. 2,653,317

HAMMER TYPE STAPLING MACHINE med sept. 1, 1951 1o sheets-sheet e Sept.29, 1953 w. R. BECKMAN E-r AL 2,653,317

HAMMER TYPE STAPLING MACHINE Filed Sept. l, 1951 l0 Sheets-Sheet 7 I c'af terapias b yw'ww .Z 5.5

Sept. 29, 1953 w. R. BECKMAN Er AL 2,653,317

HAMMER TYPE STAPLING MACHINE Filed sept. 1, 1951 1o sheets-sheet 8 Sept.29, 1953 Y E w. R. BECKMAN Er Al. 2,653,317

HAMMER TYPE sTAPLING MACHINE Filed Sept. l, 1951 i 10 Sheets-Sheet 9'my' 57 IQ -75.25 V- 54" Sept- 29, 1953 w. R. BECKMAN Er Al. 2,653,317

HAMMER TYPE STAPLING MACHINE 10 Sheets-Sheet l0 Filed Sept. 1,Y 1951 ff@@@cfffizg Patented Sept. 29, 1953 HAMMER TYPE s'rAPLING MACHINE WilliamR. Beckman and Arthur G. Schilke, Chicago, and Charles E. Crooks,Evanston, Ill., assignors to Spotnails, Inc., Evanston, Ill., a co1'-poration of Illinois Application September 1, 1951, Serial No. 244,806

40 Claims.

1 l The present invention relates to improvements in stapling devicesand is more especially concerned with Staplers of the manually operabletype that have a handle by which the device can be wielded like a hammerto strike against a surface into which a stap-le is to be driven onimpact. An important object of the present invention is to provideimprovements in stapling machines and more especially, though notexclusively, hammer type staplers, of the kind which are subject ltorough and hard usage under extreme conditions. l

Another object of the invention is to provide an improved staplingmachine which is adapted to form and sever and drive staples supplied inhat blanks in a continuous strip.

A further object of the invention is to provide a stapling machinehaving an extremely short effective driving stroke.

Still another object of the invention is to provide improvements instapling machines effecting high operating eiciency with Van unusuallysmall number of rugged operating parts.

Yet another object of the invention is to provide novel means in amanually operable stapling machine for servicing and loading the same.

A still further object of the invention is to provide improved stapleblank feeding means in -a stapling machine.

It is also an object of the invention to provide an improved manuallyoperable stapling machine that can be produced economically -by massproduction Imethods of manufacture.

Other objects, features and advantages of the presentl invention will bereadily apparent from the following detailed description of certainpreferred embodiments thereof, taken in conjunction with theaccompanying drawings in which:

Figure 1 `is a side elevational view of `a hammer stapler embodyingfeatures of the invention;

Figure 2 is a top plan view of the stapler;

Figure 3 is a front elevational view of the stapler Figure i is afragmentary side elevational view of the head end portion of thestapling machine showing the relatively reciprocable head casing andanvil structure partially removed;

Figure 5 is an enlarged vertical sectional view taken substantially onthe line V-V of Fig. l;

Figure 6 is a fragmentary enlarged sectional view taken substantially onthe line VI-VI of Fig. 1;

Figure 7 is 'an enlarged fragmentary elevational detail view takensubstantially in the plane of line VII- V11 of Fig. 6;

Figure 8 is a schematic perspective view of a strip of sheet metalstaple blanks;

Figure 9 is lan enlarged fragmentary sectional detail view through theforward portion of the stapling machine taken substantially on the linevIX--IX of Fig. 3;

Figure 10 is a sectional detail view similar to Fig. 9 but showing therelationship of parts at the completion of a driving stroke of themachine;

Figure 11 is a fragmentary enlarged elevational detail view of the lowerportion of the staple feeding mechanism in association with the anvil atthe extreme, overdrive end of a driving stroke;

Figure 12 is a schematic perspective view demonstrating a step in theloading technique for the present machine;

Figure 13 is a fragmentary perspective detail view of the lower portion4of the exposed driving head structure of the machine turned'upside downto show the manner in which the starting end of a staple blank strip issecured as an incident to loading the machine;

Figure 14 is a fragmentary bottom plan view, partially in section, ofthe underside or lower end of the driving head and staple feedmechanisms;

Figure 15 is an enlarged fragmentary detail sectional view takensubstantially on the line XV-XV of Fig. 9;

Figure 16 is an unassembled top plan view of the striker base and anvilsupporting member of the machine;

Figure 17 is a side elevational view of the base and striker member;

Figure 18 is a side elevational view of the anvil block member of themachine;

Figure 19 is a front end elevational view of the anvil block member;

Figure 20 is a fragmentary vertical sectional view taken in an irregularlongitudinal plane through the front end portion of a modified hammerstapler according to the present invention;

Figure 21 is a fragmentary sectional detail view taken substantially 0nthe line XH-XXI of Fig. 20;

Figure 22 is `a rear elevational view, partially in section, and withcertain parts removed for purpose of clarity, taken substantially on theline XXII-)DHI of Fig. 21;

Figure 23 is a fragmentary sectional detail view through the front endportion of a further modied hammer stapler construction according to thepresent invention and taken in a generally longitudinal vertical plane;

Figure 2e is a rear elevational View taken substantially on theirregular section line XX EXW or Fig. 23; and

Figure 25 is a perspective exploded assembly view of a portion of thefeed mechanism of the modified form of Figs. 23 and 24.

While it will be appreciated that certain features or" the presentinvention may have utility in stapling machines generally, whether ofthe stationary or portable types, principal attention herein is directedto the provision of a compact, eiiicient hammer stapler or" extremelyhigh load capacity and great ruggedness as well as foolproof qualities.More especially, the invention is directed to the provision of a staplerfor utilizing nat sheet metal staple blanks (Fig. 8) which are suppliedin series in a continuous strip of desired length coiled into a roll 3|.Each of these staple blanks 3Q is connected te the immediately adjacentblank or blanks by a narrow, readily severable connecting neck 32.Centrally of the coil or roll 3l is a hub or spindle opening 33.

As best seen in Figs. 1, 2 and 3, a hammer stapler embodying the presentinvention, and capable oi being loaded with sheet metal strip staplerolls 3| of 1500 to 2000 blanks, comprises a body portion 31! includinga rear handle section Se, an intermediate magazine section 3'? and aforward head section 38.

By preference, and for purposes of economy, the body portion 34comprises a shell made up from a pair oi complementary sheet metalsections that can be economically stamped into form and are thenassembled and either Welded integrally into the complete shell orsecured together permanently by means of rivets 39 accommodated withininset portions 40 in the handle section 35, and rivets 4| extending insecuring relation between the forward portions of the body shells in theforward part of the magazine section si. At its rear end the handlesection 35 is preferably provided with a downwardly projecting boss orlug d2 serving as an anti-slip stop behind a users hand, or moreparticularly behind the iittle nger of a users hand. The magazinesection Si is enlarged both vertically and transversely to accommodatethe large roll of staple blanks.

One side of the magazine section 31 is provided with an opening is(Figs. 5 and 9) large enough te receive one of the staple blank rolls 3|therethrough for loading into the magazine. For reiniorcement, the wallof the body casing 34 has an inturned flange 44.

Secured within the magazine section 31 is a staple roll container whichis preferably in the form of a generally cup shaped shell of sheetmaterial having the base portion thereof resting against the inside faceof the housing wall opposite the opening 43 and with the wall of thecontainer shell of a diameter to t within the opening i3 as defined bythe ange 44. Both the base wall of the container shell G5 and thehousing wall against which it rests are preferably bowed outwardly asseen in Figs. 2 and 5 and are provided with complementary insetinternested bosses All and te, respectively, secured together as bymeans of a rivet 49. By preference the bosses l1 and 48 are coaxial withthe opening 43, and a tubular hub 5B is mounted by means of a radiallyoutwardly extending foot flange 5| on the inner face of the containershell base Wall about the boss Li'. By preference the ange 5| is weldedor brazed in place. The external diameter of the hub or spindle ormandrel member 50 is such as to nt freely within the central hub opening33 of one of the staple blank rolls 3| inserted into the magazine. Inorder to minimize frictional resistance to turning of the staple roll 3|within the magazine container 45, an inwardly projecting transverselyarcuate contact limiting rib 53 is provided on the annular wall of thecontainer shell so as to make line contact with the imperforatelongitudinal center portion of the outermost coil of the staple blankroll.

At its lower forward portion the annular wall of the container shell iscut out to aord a feed passage 54 (Fig. 9), and the cut out portion ofthe container wall is fashioned to pro-Vide a downwardly and forwardlydirected guide lip 55. At its extremityy the lip 55 slants toward andterminates in spaced relation to a forwardly downwardly sloping ramp 57on the forward bottom wall portion of the housing 3d below and forwardlyof the container shell L5 and terminating in a downturned roundedshoulder lip 53. To provide clearance for the feed throat 5i thereinforcing flange lf3 and the adjacent portion of the side wall of thehousing has a preferably arcuate cut out 59 of sufficient size tofacilitate digitally starting the leading end of the staple blank stripfrom the coil down into the throat and then manipulating the striponward until it projects beyond the lip 5B of the ramp 5'?.

For closing the magazine entry or loading opening d3, an openable dooror closure 69 is provided (Figs. 1, 2 and 5) which is preferably in theform of a disk of sheet material. To provide rigidity of structure, theclosure door or gate member Si) is preferably of outwardly bowedstructure and provided with a marginal fiange 5| which engages againstthe wall of the housing 34 surrounding the opening 43, with a projection62 on the flange tl to overlap the strip starting clearance recess orout out 59.

By preference, the closure gate or door is hingedly connected to thehousing 34 and for this purpose is preferably provided with an integralhinge extension 63 preferably at the rear side of the cover margin. Thehinge extension is of substantial width and is arched outwardly on aradius (Figs. 2 and 6) and then extends inwardly into a hinge slot 64 inthe wall of the housing 3d (Figs. 6 and 7). At its inner extremity, thehinge extension 63 has keeper means preferably in the form of a pair ofkeeper lugs 55 which are originally formed in the plane of the terminalportion of the hinge extension '53 and after insertion through the slot64 are twisted out of their original plane into planes intersecting theplane of the hinge terminal to prevent Withdrawal of the hinge extensionterminal. When the cover 6| is to be opened, the arched hinge extension63 passes freely into the aperture defined by the slot 64 as indicatedin dot dash outline in Fig. 6.

At its opposite or forward side, the door 5B is provided wtih anoutwardly turned lip-like handle lug 61.

In order to retain the cover 60 releasably in closed position, latchmeans are preferably provided, in the present instance comprising aresilient latch stud 68 carried by and projecting inwardly from the doorB9 and engageable releasably with a keeper annulus 69 carried by theouter end portion of the hub member 59. The latch stud has a rivet head1|] by which it is secured to the door 6B Which for this purpose isappropriately apertured. Projecting inwardly the latch stud has 'aplm'ality of complementary and cooperative resilient radially outwardlyshouldered latch arms 1| which are yieldably projectable'under pressurethrough a venturilike throat 12 internally of the keeper annulus 69 toengage yieldably and under tension against an internal keeper shoulder13 which cams the latch arms inwardly and thereby draws the latch studand the gate or door 60 into snug closed relation. The keeperannulus 69has an outwardly opening internally tapering entry throat 14 withinwhich the retaining arms or lingers 1| are compressed or stressed towardone another until they pass the restriction 12 and snap behind thecamming shoulder 69. Assembled relation of the annlus 69 within theouter end portion of the hollow hub 5U is retained as by `means of aninterlock rib 15 pressed or spun into a complementary annular groove inthe annulus.

It will be noted that the door 68 is located on the right hand side ofthe stapling hammer. This is advantageous for the reason that most usersare right handed and by having the left side of the hammer clear ofobstructions or projecting portions, but smoothly nished by the slightside wall bulge of the magazine section, it is possible to get closeinto reentrant angular places without interference. From Fig. 2, it willbe observed, moreover, that the handle has the side walls thereof insetrelative tothe side walls of the magazine section 31, and this furtherfacilitates getting into close corners.

It should. also be observed from Fig. 1 that the lower portion of themagazine section 31 projects substantially downwardly below the lowerside of the handle 35. This affords a high degree of protection for theusers knuckles when striking against a surface into which a staple is tobe driven.

The stapling hammer of the present invention is so constructed andarranged that the staple driving means are mounted in fixed relation tothe handle 35 and the magazine section 31 to take full advantage of astaple driving blow when the stapling hammer is wielded for thispurpose. To this end, the head section 38 comprises a head block 18which is xedly supported by the housing 34 immediately in front of themagazine section 31. The head block is adapted to be made as avertically elongated casting and has an upper rearwardly projecting ear19 and a lower rearwardly projecting ear 8B which extend rearwardlybetween the side walls of the housing 34 and are secured in place by thetransverse pins or rivets 4|. Respective spacers 8| (Figs. 9 and 14)maintain the ears or lugs 19 and 8D, and thereby the head block 18 inlaterally centered relation to the housing 34.

Additional support for the head block 18 is provided by respectiveopposed upper pairs of forwardly directed strap extensions 82 andrespective opposed forwardly extending pairs of lower securing strapextensions 83 (Figs. 4, 9 and 14) on the side walls of the housing andembracing the block 18. For this purpose the sides of the block 18 areprovided with respective longitudinally extending slots 84 respective ofthe upper supporting straps 82 and respective longitudinally extendingslots or grooves 85 receptive of the lower supporting straps 83 (seealso Fig. 13). The terminal extremities of the several straps are turnedangularly inwardly to provide retaining anges 81 engaging withinrespective vertically extending rabbet grooves 8B in the forward wall ofthe block 18. Respective upper and lower flu s. connecting pins orrivets 88 securely fasten the straps' and 83 to the sides of the headblock 18. Thus, the head block 18 is very securely and permanentlyattached to the front end portion of the housing 34 in a manner that cansatisfactorily withstand the stresses and strains and shocks incident tohammering use of the device in service.

At its lower end, the head block "i8 extends short of the lower endportion of the ramp 51 and thereby affords substantial passageway forextension and feed of the staple blank strip into forming and drivingposition under the head block (Figs. 9 and 10).

Supported by and projecting downwardly from the lower forward portion ofthe head block 1B is a cut-oli and driver member 33 and a former 9|.Both of these members are preferably formed as enlongated blades ofappropriate thickness and preferably of the same width and are mountedwithin a downwardly and forwardly opening recess 92 in the lower portionof the front face of the head block. The driver cut-off member lllI ispreferably longer than the former 9| and is superimposed upon the formerand the two members are secured in the recess 92 by means of a stud 93extending through aligned apertures in the driver and former members andthreaded intothe head block 18 with the outer end portion of the studcarrying threadedly thereon a lock nut and clamping member 94. A driverslot 95 enables the member 94 to be tightened so that a lateral shoulderengages in the bottom of a suitable counterbore 91 in the face of thecut-off and driver member 9i) to secure the members in position.

cooperatively related to the driving and forming members and 9| is astriker and anvil structure 98 which is reciprocably supported by thehead block 18 normally in extended relation to the members 9i] and 9|ready for striking against a surface into which a staple is to be drivenand then relative movement into operative relation to the driving andforming members for not only cut-off and driving of a formed staple S(Fig. 9) from the leading end of the staple strip but also the formingof the succeeding staple blank 30 into a U-shaped staple S (Fig. l0). Tothis end, the striker and anvil structure is reciprocably supported by agenerally tubular supporting and guide casing member 9S which may beformed from suitable gauge sheet metal into angular hollow cross sectiondimensioned to engage the head block 18 in slidable vertically guidedrelation. The front and side surfaces of the head block 18 are formed asvertical, preferably flat bearing surfaces and the supporting and guidemember 9S is internally dimensioned complementary to the bearingsurfaces. At its front wall the head block 18 provides a verticalbearing surface Hi8 between the corner rabbet grooves 88. The side wallsof the head block are preferably provided with a respective plurality ofnarrow vertical bearing ribs ||i| separated by intervening verticalgrooves |932, thereby limiting frictional contact between the side wallsurfaces of the block and the relatively slidably cooperating supportingand guide member casing 99.

At its rear side, the casing member 99 is open but is provided at therear margins of its side walls with inwardly directed angular verticalrespective guide flanges |03 (Figs. 10 and le) slidably engageablebehind rearwardly directed respective bearing shoulders |04 on the headblock and with the respective attachment strap extensions 82 and 83appropriately complementarily indented to provide clearance grooves IE(Figs. 4, 13 and lll). Through this arrangement, free vertical relativesliding, reciprocal movement of the head block 'it and the guide casing99 is permitted within operative limits, and also assembly of the casingmember 99 by relative sliding movement with respect to the head memberis facilitated.

The striker and anvil structure 9S may, if desired, be constructed inone piece, but for economy in manufacture is preferably made in twoparts comprising a striker and anvil supporting base block Ii and ananvil block H38 assembled therewith. As best seen in Figs. 9, 15, 16 and17, the striker and base block 51 comprises a preferably fiat base plateportion It front and side marginally dimensioned to engage against thelower edge of the casing member Sie a marginal fiange Ile being providedfor this purpose. At its forward edge the flange I IGI is preferablycontoured to extend beyond the forward wall of the casing member 953 asa buffer nose.

Adjacent to the opposite sides of the base plate ifi@ are respectiveupwardly projecting preferably parallel body block portions I I Idefining a longitudinal anvil block channel II?) therebetween withinwhich the anvil block IEB is received snugly in assembly. For thispurpose the anvil block Hi8 is of elongated narrow form complementary inwidth to the channel I I2. In the assembly, the base member I E11 andthe anvil block l are secured together and to the lower end portion ofthe casing member 9E by means such as connecting pin rivets iISextending through complementary, aligned pin apertures H6 and IIE inrespectively the body block members or portions I il and the anvil blockIt aligned with similar apertures H1 in the sides of the casing member9S and within which the heads of the rivet pins are peened or upset toeffect a functionally integral assembly.

The construction and relationship of the striker anvil assembly 98 issuch that in each operative stroke of the stapling hammer the driver SBsevers a formed staple from the leading end of the staple blank stripand drives the staple while the former SI forms the succeeding stapleblank into staple form. portion of the anvil member 1&8 extendsforwardly beyond the front ends of the body block and anvil centeringportions Ii! a sufficient distance to cooperate with the driver 96 byproviding a shearing or cut-off edge Ile cooperative with the rearshearing edge of the cut-01T and driving member alii in a driving stroketo sever the neck connecting the formed staple with the staple blankstrip. Rearwardly from the shearing edge H8 but forwardly of the frontends of the side supporting body portions iII, the anvil member |68cooperates with the staple former Si which for this purpose has agenerally U-shaped downwardly opening for mean slot Iiii dimensioned topass by the sides of the forwardly projecting portion of the anvilmember Hi8 to engage and bend down about the anvil member the staple legor arm portions of the next succeeding staple blank, which legs movedown in the space forwardly of the body portions i I I.

To delimit the forward position of not only the formed staple blank atthe terminus of the staple blank strip, but also the next succeedingblank, the supporting and striker block |01 carries forwardly of thebody portions I I I respective generally complementary upstanding limitstop Accordingly, the forward end standard or post members |20. Theseare disposed at respectively opposite sides of a staple exit opening |2|in the base plate |09 and provide respective vertical stop faces |22 fordelimiting forward movement of the formed staple S while definingtherebetween a space for the severed neck stub at the forward side ofthe staple. Spaced rearwardly from the stop shoulders |22 are respectivestop shoulders |23 which oppose the ends of the body portions III andprevent overrun of the staple strip by opposing the forward edges of thelaterally projecting legs or arms of the next succeeding staple blank inthe forming space at the sides of the anvil block.

Immediately rearwardly of the stop shoulders I 22 tapered or curved leadin cam surfaces |24 are provided on the respective stop standards |26and complementary to one another and directed toward the exit opening|2| for positively camming the tips of the staple S when driven towardand through the opening I2 I. It will also be noted that the forward endof the anvil member |58 is tapered downwardly and rearwardly asindicated at |25.

In order to provide backlash preventing means for the staple strip andalso to restrain the staple legs against rearward tilting duringseverance of the staple from the strip, novel means are provided, hereincomprising resilient back up members |21. In a practical form thesemembers comprise elongated bowed resilient leaf springs preferablyformed from tempered spring material. To accommodate the spring members|21, the anvil |68 is provided with respective longitudinal grooves |28at its opposite sides and intersecting the upper portions of the pinapertures II5 (Figs. 9, 18 and 19). The grooves |28 are deeper than thethickness of the spring members |21 but are shallower than theunstressed bowed arc of the spring members. In assembly the springmembers |21 are inserted in the grooves |28 and stressed toward attenedcondition therein with the backs of the bowed springs within the groovesand bearing against the anvil block. Then the anvil block is assembledwithin the channel I I2 so that the inner walls dening the body portionsI I I confine the spring members |21 in their stressed condition withinthe grooves |28. Longitudinal displacement of the leaf spring members isprevented by engagement of the leaf spring members with the securingrivet pins II3, for which purpose the spring members are appropriatelycomplementarily notched as at |29.

The forward end portions of the restraining spring members |21 extendforwardly alongside the forwardly projecting portion of the anvil member|08 and to a limited extent beyond the forward tip of the anvil membersufciently to flare out laterally and engage behind the respective legsof the formed staple in the staple driveway and more especially againstthe rear edges of the legs. The arched or bowed condition of therestraining spring members I 21 is properly calculated so that with theforward portions of the spring members spread against vertical cornershoulders |30 provided at the forward ends of the body portions I I atthe anvil grooves |28. the spread apart forward tips of the springmembers will properly engage behind the rear edges of the staple legs.At their rear tips, of course, the spring members |21 engage understress or tension against the side walls of the body portions IIIclosing the anvil grooves |28, By reason of the resilient flexibility ofthe spring members |21, the forward tip portions can flex into theforward portions of the anvil grooves |28 as an incident to forming ofthe staple legs at the opposite sides of the anvil nose portion. Then,when the staple blank strip is fed forwardly the forward tip portions ofthe spring members will snap open and into stop or restraining positionbehind the staple legs.

The construction and arrangement of the striker and anvil structure 98and the supporting tubular casing 99 and the relationship thereof to thehead block 18 are such that the striker and anvil structure 98 normallyprojects down-r wardly a substantial distance below the lower end of theramp 51 (Figs. 1 and 9) to a suiiicient extent to clear ther cut-olf andstaple-forming members 99 and 9| above the anvil |98 for feed ing of thestaple blank strip into position between the anvil block and theforming, cutoff and driving members, and further, such that at thecompletion of a driving stroke the lower' surface of the striker memberbase plate |09 will be in a plane under the ramp lip 58. To thisV end,in the form of the invention shown in Figs. 9, and le, the lower orcut-01T and driving end tip of the member 90 is disposed to extend to alower elevation than the ramp lip 58 and the striker and anvil structureis normally biased to extend downwardly into clearance relation to thecut-off and driver tip as best seen in Fig. 9.

Eiricient biasing means comprises a spiral compression spring |3|mounted within a vertical downwardly opening bore |32 in the head block18 and bearingA under compression against abiasing plunger |33reciprocally slidably guided in the bore |32. At its lower end theplunger |33 carries a biasing shoe |34 which normallybears down againstthe anvil |08.

By preference, the shoe |34 performs, in. addition to its biasingfunction, the functions of a staple strip guide means, a staple striphold-down lever, and a staple strip attening means. To this end', theshoe member |34 (Figs. 9, l04 and 14) preferably comprises a suitablegauge sheet metal member having spring characteristics and provided withspaced parallel upstanding ears |35 whichv engage the lower end portionofthe plunger |33 within respective recesses |31 and are connected tothe plunger by means such as a rivet pin |38'. Thereby the shoe member|34 is secured in engagement with the lower end of the plunger |33'which. engages against the upper surfacel of the body of the shoe.

At its forward end portion,` the shoe member |34 is constructed toprovide a resilient strip hold down spring lever. To this end theforward end portion of the shoe member comprises an elongated narrowspring finger extension |39 normally extending slantingly downwardly andforwardly and terminating in a substantially at horizontal hold down pad|40 which is disposed toengage upon the upper surface of the centralportion of the staple blank strip on top of the forwardly projectingforming nose portion of the: anvil |98. Thereby, the biasing pressure oftheshoe |34 is exerted effectively upon the` anvil 98 under the formingmember 9| and serves the further desirable functionv of a stripper toassure. stripping of the formed staple blank from, the former.

At its. rear portion, the shoe memberV |34 is pro= vided with aArearwardly and upwardly curving' strip defleetor and guide tail |4|which extends rearwardly and upwardly relative to the lower end portionof, the plungery |233- and. normallyvr the extended condition of thehammer head assembly lies in spaced opposition to the forward edge ofthe throat lip 55 and the ramp lip 58 to guide the staple blank stripsmoothly toward the forming and driving station between the hold downfinger extension |39 and the anvil |98.

Strip guiding assistance, cooperative with the shoe |34 is afforded byupstanding curbs |42 provided along the outer longitudinal margins ofthe striker and supporting body portions to project upwardly above thepreferably common plane of the top of the anvil |08 and the tops of thebody portions inside the curbs |42. There is thus provided a guidewayabove the anvil down into which the shoe |34 normally constantlyprojects as best seen in Fig. 9. By preference the curbs |42 haveforwardly convergently tapering guide walls |43 (Fig. 16) to accommodatethe staple strip with minimum resistance from engagement with the tipsof the staple blank legs.

When a staple is to be driven, the hammer stapler is wielded like anordinary hammer to drive the at bottom of the striker plate |69 againstthe surface into which a staple is to be driven. The nat bottom of theplate E99 thereby comes to rest upon the surface and inertia carries thedriving' head 'i9' downwardly toward the strikv er and anvil assembly98, compressing the biasing spring |3-| andl carrying the cut-off anddriver member Bt and the staple forming member 9| downwardly intooperative relation to the anvil |93 and further the leading end staplehas been, driven intoz the impacted surface and the next staple blankformedv into the staple shape, substantially as seen in Fig. l0 whichshows the relationship of parts just short of the final increment ofmovement in thev drivingY stroke. It will be clear, of course, that asthe spring |3| is compressed, correspondingly greater pressure load is,exerted against the shoe member |34 through the plunger |33 so that Athehold down and pressure finger' |39 gradually fiexes resiliently towardflattened condition. Then, as best seen in Fig. 11;, at the conclusionof the. driving stroke there is. a slight overdrive which causes the`shoe. member |34' to against a plurality of` the successivev stapleblanks 39 behind the newly formed terminal staple S.. As av result theend portion of the strip including' several ofthe staple blanks 3Uisquite effectively flattened against the anvil |118 and. all surfaceirregularities or kinks that may possibly be' present in. the strip andwhich might cause disruption of proper functioning of the mechanism,arev thoroughly ironed out. Immediately upon dissipation of the drivingblow energy, the spring |3| expands and returns the mechanism to theinitial relative position of the parts, in` readiness for another stapledriving and forming blow.

As an incident to the staple driving and return strokes of the headmechanism,I means are operatedY for feeding by one staple incrementforward'ly so that' the newly formed staple is advanced intothe drivingthroat ofthe device automatically as an incident to return ofthemeehanism to the initial position. To this end, a yoked feed fingermember |44 (Figs. 9, 1'0 and f4) is provided which has/a pair ofidentical feed fingers |45 directed forwardly above the forward tipportion ofthe Vanvil W8 and is: pivotally connected as by means of'A aconnecting pini ttl to the lower end portion of: a. feed leverA |48'which. extends upwardly within av downwardly opening slot i919" in the.plunger |33 and is rockably connected adjacent` to itsf upperendlwithirr said slot by means of a connecting pin |58. A yoke-typetorsion spring has the yoke end portion thereof engaging against theflat yoke portion of the feed finger lever member |44 and has torsionarms thereof engaged about appropriate laterally projectingtrunnion-like anchoring pins |52 at opposite sides of the lever |48. Thespring 5| acts not only to bias the feed finger lever |44 downwardlyinto feeding engagement relative to the anvil member and the stapleblank strip, but also acts normally to effect a forward bias of thelower portion of the feed lever |48 due to the torsional relationshipwhereby the lowermost of the engagement pins |52 is engaged within theforwardly opening reentrant angle of the spring legs and the uppermostof the connecting pins |52 is engaged by the terminal portions of thespring legs while the spring is tensioned to tend normally to straightenout from the angled relationship shown in Fig. 9.

As the mechanism approaches the staple driving portion of the drivingand forming stroke, a plunger |53 slidably reciprocably guided in a bore|54 in the head of the plunger |33 has the upwardly projecting endthereof engaged by a downwardly directed head |55 of an adjustableabutment stud |51 carried by the upper end portion of the head block 18and projecting downwardly into the bore |32 within the biasing spring|3|. As the upper end of the plunger |53 engages the fixed stop head|55, and is thereby halted in upward movement, a head |58 on the lowerend of the plunger |53 normally engaging against a rounded head |59 atthe upper end of the lever |48 forwardly of the pivot or rocking axis ofthe lever, causes the lever |48 to swing positively about the axis ofits pivot to carry the lower end portion thereof rearwardly and thusmove the feed finger member |44 likewise. Thereby the feed fingers |45are drawn back behind the newly formed staple blank S in readiness tofeed the same forwardly into driving position at the completion of thereturn stroke of the mechanism.

In view of inevitable manufacturing tolerances and other factors whichmake it desirable to adjust the feed rocking stroke of the lever |48,the abutment stud |51 is preferably adjustably mounted. For this purposethe stud |51 is threadedly secured in a bushing member |69 securedwithin a bore |6| in the top of the block member 13. By preference thebushing |60 is centered with relation to the axis of the plunger |33 andhas a flange |62 that serves as a seat for the upper smaller end of thespiral compression biasing spring |3|, and also seats in thrust relationagainst the roof of the bore |32.

For adjustment purposes, the upper end of the stop stud |51 is providedwith means such as a slot |63 for effecting threaded adjustment thereofby means of a screwdriver or the like. Proper adjustment is effected onthe assembly bench. Once the proper adjustment has been found for theassembly, the stud |51 need not be further adjusted. Therefore means areprovided to immobilize or neutralize the adjustment and also to lock theadjustable stud |51 against tampering. To this end the relationship issuch that a substantial cavity is provided within the bushing |69 abovethe end of the stop stud |51 after adjustment has been effected and thiscavity is lled with a sealing material such as solder |64. Solder or asimilar material can be readily removed by the application of heat tomelt the same if it becomes necessary, due to repairs or wear to servicethe machine and effect a new adjustment.

In order to assure clearance of the feed ngers |45 from the path of thedriving and cut-off member at the commencement of a driving stroke, theforward edge of the feed lever |48 is provided with a cam surface |65against which the inner end or tip of the adjustable stud 93 engages todrive the lower end portion of the lever |48 rockably inwardly a limitedinitial distance. For adjustment the stud 93 is threadedly secured intothe forward portion of the head block 18, with its inner end or tipappropriately adjusted with respect to the particular requirements ofthe rockable feed lever |48.

At the end of a return stroke of the mechanism, the feed lever |48 ispositively rocked in the feeding direction by engagement of anoverhanging upper end forwardly projecting finger |61 thereon against anabutment provided by a bar or pin |68 which traverses the bore |32 abovethe abutment and booster pin 93. The bar |68 functions also to retainthe plunger |33 against turning in the cylindrical bore |32, and theplunger therefore has a forwardly opening clearance slot or cut-out |69providing vertical bearing surfaces which normally clear the bar |68 butwill engage the same on any tendency of the plunger |33 to turn out ofposition.

From Fig. 9 it will be observed that the feed thrust or booster bar |68and the stud 93 are cooperatively related to retain the feed lever |48against centrifugal forward rocking during a. driving stroke and alsoagainst any tendency to rock backwardly for any reason. By having thetip of the stud 93 engage the lever below its pivotal or rocking axisforward swinging of the lever' is positively limited. By having thefinger |61 engage the thrust bar |68 at the end of the feed stroke,rearward inadvertent movement of the lever is prevented.

It has also been found in practice that if for any reason a staple hasnot been fully driven during a driving stroke, it can be hammered homeby driving the substantial rearward striking surface of the strikerplate |09 thereagainst. Sufficient force for such supplemental drivingof a partially driven staple can be generated without driving the nextsucceeding staple or disrupting the feed mechanism. Thereby the hammerhas proved to be substantially jam-proof.

For air pressure relief, the upper portion of the bore |32 is ventedthrough an opening |69 which preferably opens to the interior of themagazine section 31.

Loading of a fresh staple blank strip into the head section 33 isaccomplished simply by sliding the carrying and guide casing 99 off ofthe head block 18, as: indicated in Fig. 4 to expose the lower endportion of the driving mechanism substantially as shown in Fig. 13. ltwill be assumed that a fresh roll 3| of staple blanks has been placed inthe magazine section 31 and the end portion thereof projected from thefeed throat 54 into position opposite the shoe member |34. rThen, bysupporting the machine in the inverted position shown in Fig. 13, theend portion of the staple blank stripis grasped between the foreiingerand thumb of one hand, substantially as shown in Fig. l2 and the leadingor terminlal staple blank 39 is hooked in front of a pair of loadinglever fingers |19 and behind respective loading shoulders |1| at theback of the feed fingers |45, in the manner shown. The loading fingers|19 are preferably provided on a generally yoke-shaped ngerlever membersimilar to the feed finger member |44 but shorter and pivotally mountedat its rear end portion upon the pin |38 by which the ears of the shoeare con nected to the bottom portion of the plunger |33. A torsionspring |12 wound about the pin |38 operatively engages at its forwardend with the forward end portion of the loading finger lever member andat its rear end portion bears against the rear end portion of the shoe|34. By the operation of the spring |12, the loading finger lever isnormally biased downwardly as shown in Fig. 9 and upwardly as shown inFigi. 13 into a position where it will not interfere with normaloperation of the feed finger lever member |44. In the loading position,the spring |12V biases the loading finger |10 to shoulder at |13 againstthe shoe member |34 to assume the loading position wherein the forwardlyslanting forward edges of the loading fingers |10 are in position tohook behind the rear edges defining the legs of the terminal stapleblank 30., while the shoulders |1| of the feed fingers engage under thebias of the spring |5| iirmly against the forward edges defining theterminal staple blank legs. As a result, the terminal blank of thestaple strip is quite rmly held until the casing member 99 isreassembled with the head block 18 and the assembly completed, ready foroperation. In this retained position of the terminal staple blank, it isproperly located to be formed upon the initial driving stroke. Then, ofcourse, it is automatically fed forward so that on the succeeding strokethe staple will be driven and the next succeed-y ing staple blank formedinto the staple shape.

Because of the firm grip of the staple strip by the hold down plad |49of the biasing shoe |34, as well as. the retraction preventing functionof the spring members |21, no additional hold back means is required,but the loading fingers are so located, as best seen in Fig. 9 that theyserve as emergency hold back fingers should the need arise. Normally,however, the loading 1ingers |10 :are idle during normal operation ofthe machine.

In order to enable the machine to utilize staple blank strips of variouswidths, the feed iingers |45, and preferably also the loading fingers|10 are constructed to serve as centering means forthe staple strip. Tothis end, having particular reference to Fig. 14, the feed lingers |45and the loading lingers |10 lare respectively divergently relatedstraddling the hold down finger i39 to engage the opposite sides of thenecks between staple blanks cammingly to center the strip longitudinallyin the guideway over the anvil |08 and under the shoe |34.

Releasable means are provided for retaining the casing member 99 inoperative relation on the head block 18 in the non-operating or fullyextended condition of the striker and anvil structure 98v relative tothe driving end of the headblock 18. To this end a releasable head latchmember |14 is mounted on theV upper or head endv portion of the casingmember 99 for closing the normally open end of the casing member. Bypreference the latch member |14` comprises a sheet metal stamping ofappropriate gauge (Figs. 1, 2, 3, 4 and 9) which is of a Width to seatvclosingly uponthe upper ends of the sidewalls of the casing member 99yand has the forward end portion provided with a hinge curl |15 hingedlyconnected by a pin lil to and between a, pair of forwardly projectingspaced' parallel hinge ears- |18 struckoutfrom the upper portion 14 ofthe front wall of the casing member 99. At its rear end portion thelatch member |14 has an upwardly directed lip-like handle |19.

Means for releasably securing the latch gate member |14 in positioncomprise in the present instance a pair of upstanding ears respectivelyprovided on the upper edges of the casing member 99 and projectingthrough respective slots |8| in the member |14 and closely dimensionedwith respect to the ears |80 in width while amply clearing the same atthe ends of the slots. The ears |80 have transversely aligned holes |82therein receptive of releasable locking pin structure comprisingrespective locking pins |83 formed integrally in one piece with aresilient locking pin member |84 carried on top of the latch grate plate|14. Journal straps |85 struck up from the top of the latch plate |14-provide journals or sockets for the pins |83 aligned with the openings|82. The member |84 is yoke shaped and dimensioned longitudinally to lieagainst the upper face ofthe latch plate |14 between the straps |85 andwith the connecting yoke portion thereof complementary to and lyingagainst the handle portion |19 of the latch member. Extending forwardlyand connecting the yoke portion of the member |84 with the pin members|83 are respective digitally engageable loops |81.

The member |84 is formed from resilient material such as appropriategauge spring wire and is. resiliently deflectable by compressing theloops |81 toward one another for withdrawing the pin portions |93thereof from the ears |90 to release the member |14. The spacing betweenthe legs of the yoke of the member |04 is predetermined to limitwithdrawal of the pins |93 to the extent necessary to release the samefrom the ears |80 but not from the straps |85-, To effect relocking ofthe latch member E14, it is returned to the locking position and thepins |83 returned to the locking relation with the ears |89.

In addition to serving as locking ears, the ears |99 Serve also as formretaining means for the upper portion of the casing member 99 and moreparticularly the side walls thereof since by the interengagement of theears |89 through the closely fitting slots lill, spreading o-f the sidewalls of the member 98 is substantially precluded in the upper portionthereof in service. The lower portions of the side walls of the member 99 are, of course, retained firmly in position by the connecting rivetpins H3.

In the modification shown in Figs. 20, 21 and 22, the principaldifference over the form of the invention that has just been describedresides in the driving head portion of the machine. The basic mode ofoperation and structure are substantially the same in this modificationas in the rst-described form. Therefore identical or substantiallyidentical parts of this modification will be identiiied by primedreference nu-A merals corresponding to the same reference numerals ofvthe first-described form and specic description of the correspondingyelements or parts will be dispensed with for the sake of brevity. Itwill be understood, however, that the cooperative relationship andfunction of the parts identified by primed reference numerals is thesame as described in connection with the lirstdescribed form of theinvention except as modifiedl by the immediately following description.

The principal difference in the modication of Figures 20 tov 22 residesin the modified arrangements for biasing the striker and anvil4 assemblyand for incrementally feeding the staple strip into forming and cut-offand driving position, and without the use of a biasing and feedmechanism supporting plunger as in the first-described form oi theinvention. To this end, biasing of the striker and anvil structure SSams the supporting and guide casing 95E normally into extended positionto the extent permitted by the top closure member iM is effected bymeans such as elongated, narrow respective coiled compression springsE83 disposed at thev opposite sides of the head block le. The biasingsprings |88 are accommodated in vertical position throughoutapproximately half their diameter within respective vertical clearancegrooves er channels ESS in the sides of thc head block l', andthroughout the remainder of their diameter within laterally protrudingvertical interiorly hollow respective bosses i953 provided in the sidewalls of the casing member Se. At their upper ends the springs |88 bearagainst respective downwardly facing thrust shoulders it! provided atthe upper ends of the respective grooves |89 in the head block. At theirlower ends, the springs 53S thrust under compression load againstrespective thrust shoulders i922 provided at the lower ends of thebosses ld of the casing member. Through this arrangement, the casingmember 9d and the striker and anvil structure et supported thereby arenormally biased toward the maximum extended condition relative to thehead block ld but will yieldably move reciprocably relative to the headblock 'i8' in response to a staple driving and forming blow of thestriker itl' against a surface into which a staple is to be driven.

The feed lever lil-3 is supported reoiprocably within the head block SSdirectly within a vertical rearwardly opening clearance slot |93 in thehead block. This is accomplished by mounting the lever it upon a pivotpin or shaft member idd which is freely vertically movable through atransverse slot it in the head block i3 and elongated vertically toafford a full range of vertical reciprocal movement of the lever M8 withthe anvil and striker structure Q8. The opposite end portions of therocker shaft or pivot pin |255 extend through the respective oppositeside walls of the casing member eil and are held in assembly againstendwise displacement by means such as split snap ring washers |91fitting in suitable annular grooves in the end portions of the shaft.Thus, as the casing member S9 moves reciprocably relative to the headblock i8 the feed lever ifl' is carried correspondingly reciprocablywithin the slot |93 in the head block between the full line and dot-dashline positions shown in Fig. 20.

it the end of a driving stroke of the mechanism, the head i of the feedlever engages against the lower end or tip of a xed stop stud member istwhich corresponds in function to the plunger |53 and 'the abutment stud|51?, previously described. The abutment stud |95 is disposed on anoffset forwardly from the pivotal axis of the lever ii appropriately toeffect rearward swinging of the lower portion of the lever ills at thecompletion of a driving stroke of the device. For this purpose the studS93 is threadedly secured adjustably through a vertical threaded boreESS in the tcp portion of the head block T8', withr adjustment effectedthrough the top of the head block in the same manner as adjustment ofthe stud ll is effected, and similar adjustment-retaining and 16anti-tampering means may be provided after bench adjustment has beenattained.

Support for the hold down and guide shoe |34 and for the loading fingers|10 is provided by the striker and anvil supporting block body memberlill. To this end, the side portions are provided with upstandingintermediate respective bosses 200 providing end support for thesupporting pin |33 for the connecting ears |35 of the shoe member |34and for the loading inger member as well as for the biasing spring |13.The pin |38 is, of course, somewhat longer than in the rst-describedform of the invention. To hold the shoe |34 against rocking about itssupport, the ears |35 are preferably provided with respective outwardlydirected front and rear interlock tabs or extensions 20| engaging withinrespective rabbet grooves 202 in the front and rear edges, respectively,of the bosses 20d. Thus, instead of riding with the feed iinger andlever assembly, the shoe |34 and the loading nger member ride with thestriker and anvil support member |91. However, the feed, hold-down shoeand loading nger mechanism are actually all supported to move with thecasing member 99 in operation. It will be noted that respective spacersleeves 203 are provided between the shoe supporting ears |35' and theloading finger member to maintain the latter in centered relation. Sincethe feed fingers |45' straddle the loading fingers I'Hl the feed ngermember |44 is also maintained in centered relation.

To facilitate loading of the machine with a staple blank strip from acoil Iwithin the magazine section 3l', the lower portion of the housingat the strip delivery throat 54 and at the rear portion of the ramp 51is provided with a clearance cut-out 2M so that the end portion of astaple blank strip can be grasped between the thumb and a finger of ahand of the user and pushed forwardly between the shoe member |34' andthe anvil member |08 until the leading staple blank has passed theloading ngers |113. The machine is then ready for continuous andrepeated use until the staple strip has been completely used up.

Should it be necessary for any reason to disassemble the head portion ofthe machine, that can be quickly elected by releasing the rock shaft orpin member |94 and withdrawing the same, whereupon the casing member 99can be slidably separated from the head member 18' after opening of thelatch member |14.

In the modification shown in Figs. 23, 24 and 25, a ratchet and starwheel feed arrangement is shown for advancing the staple blank strip.Inasmuch as the general mode of operation and the housing and headstructures, including the magazine section, the head block structure andthe reciprocable striker and anvil structure are in several respectsidentical and in certain respects substantially the same as in thefirstdescribed form of the invention, corresponding elements have beenidentified by double primed similar reference characters and it will beunderstood that the elements thus identified have the same functions inboth forms of the invention.

A normal extended relation of the striker and anvil structure 9S" andthe slidably guided casing member 99 with respect to the head block 18is maintained by biasing means including an elongated plunger 205 ofgenerally rectangular cross section urged into the extended relation bya pair of torsion springs 201 acting between the head end of the plungerand the roof of a guide slot 208 within 'which the plunger is verticallyreciprocably guided slidably in the head block 18". The springs 201 areof the type vhaving torsion arms extending from a loading coil, 'and onearm of each spring thrusts against the upper end of the plunger whilethe other varm thrusts against the roof defining the slot 20B. Atransverse pin 209 supports the springs 201 at the coil portionsthereof.

At its lower end the plunger V205 carries the shoe member |34l and whichbears down against the anvil |08 within the staple strip rguide channel|43.

At each operating stroke of the mechanism a star wheel feed vmechanism2|0 advances the staple blank strip by one staple blank toward thecut-01T and driving member 02" and the staple forming member 9|." VTothis end, the .star wheel feed mechanism 2|0 includes a pair :ofpreferably identical star wheel feed members 12|| having staple blankengaging and advancing lugs or teeth 2|2 projecting uniformlyperipherally and disposed in transverse alignment as `the star wheelmembers are coaxially pivotally mounted on a pivot pin 2|3 extendingtransversely through the lower portion of the plunger .205 so that thestar wheel assembly -is rotatably mounted within -a slot 2|4 in theplunger. The .mounting of the star wheel assembly is such that vthelower portion of the peripheries of the star wheel .members 2|| projectdown through respective slots 2|5 provided longitudinally to accommodatethe same inthe shoe member |34". Thereby the lugs 2|2 on the star wheelmembers are engageable between successive ones of the staple blanks 30".It will be observed that in order to provide clearance for the starwheel feeder lugs 2|2 in the final phase of the driving stroke, and moreespecially during the spanking overdrive terminal portion of the stroke,the top of the anvil |08 has a spaced pair of clearance grooves 2 I1therein.

Incremental staple blank advancing rotation of the star wheel feedmechanism 2m is effected by means of a feed pawl '2 |'8 operativelyengagen ally mounted on a pivot pin 220 that .extends y through theupper or butt end of the pawl and is vertically reciprocably guidedwithin aligned slots 22| in the walls of the plunger 205 dening the slot2|4 so that the pawl may have an vadequate range of verticallyreciprocal movement for successive engagement .by its dependingratchet-engaging tip with the ratchet teeth of the ratchet member 2 I9.y

Reciprocations of the pawl 2|8 are effected automatically in theoperation of the stapling hammer by means of a bell crank member 222which is pivotally mounted on a pin 2 23 within the upper portion of theslot 2|4 of .the plunger and has an arm extending rearwardly intopivotal connection by means of a pin 224 with 'a pair of preferablyidentical links 225 extending down into pivotal connection with the pawl2 I8 through the. medium of the pivot pin 220.

Near the end of a driving stroke of the machine, an upwardly extendingarm or head 221on the forward portion of the bell crank member 22,2engages a camming head 22.0 projecting downwardly from an adjustablestud 22.0 threaded into the top of the head block 18 and ac` cessiblefor adjustment .from von top of the head block. This causes the 'bellcrank 222 to be rocked -counterclockwise about its pivot 223, as seen inFig. 23 and .this draws the links 225 and thereby the pawl '2|8upwardly. The adjust- .ment of the camming head 228 is such that upwardmovement of the pawl 210 is sufcient to -clear the next succeeding toothon the ratchet member 2|^9 so that a pawl biasing spring 230 will snapthe driving tip of the pawl into engagement with the next ysucceedingratchet tooth.

In a convenient form, the pawl `biasing spring :comprises a resilientleaf spring having a head portion 23| provided with lateral oppositelydirected coplanar flanges 232 which are received in assembled relationwithin respective complementary vertical slots 233 in the links 225.Thereby the spring 230 is `carried by the pawl actuating lever and linkmechanism and constantly biases the pawl toward the ratchet vbyengagement with the back of the pawl below its pivot.

Staple blank advancing thrust is imparted to the `pawl 2'1'8 at the endof the return stroke of the driving head mechanism, and moreparticularly at the end of the return stroke of the plunger 205 underthe bias of the spring 201. To this end, an abutment stud 23'4 isthreaded through the front wall of the 'hea-d block 18 above the recess92 to position a rounded tip 235 on the inner end of the stud forengagement by a cam face 231 on the forward side yof the vbell crankhead 221. Thereby, when the plunger 205 returns to the fully extendedrelation thereof to the head block 18", the cam face 231 engages theabutment tip '235 and causes the bell crank member 222 to rocklclockwise as viewed in Fig. 23 for driving the links 225 and therebythe pawl 2| 8 ldownwardly for advancing the star wheel mechanism by oneratchet tooth increment which is properly calculated to advance thestaple blank strip one staple blank forwardly.

`Serving as a retainer for the upper portion of the plunger 205 and as apartial closure for the rear, open side of the slot or plunger guidewayrecess 203 in the head block 18, is a plate 238 which may be `secured asby means of screws 239 across the upper portion of lthe slot 208 inclearance relation below the springs 201. The lower portion'of the plate238 is offset outwardly to clear :the pawl biasing spring 230.Additional retaining bearing means for the plunger 205 and disposedadjacent to the lower end of the plate 238 are provided by inwardlyextending bearing portions of the attachment ears as best seen in Fig.24.

Loading of a new staple blank strip into the machine of Fig. 23 iseffected by removing the casing member 99 with the anvil and strikerstructure 98", after opening the closure member |14". 'I'hereupon theend of a new staple blank strip fed down the feed throat 54" is engagedupon the strip feed star wheel 2 2 and held in place by the loadingfingers |10 engaging behind the terminal staple blank 30. Duringloading, the thrust of the plunger-engaging legs of the biasing springs201 is absorbed by the 'upper edge of the guide and closure plate 238,serving as a loading thrust immobilizing abutment for the spring legs.The relationship is such, however, that when the striker and anvilmechanism 98" and the supporting and guide casing 99 are replaced uponthe head block 18" and the latching closure member |14 is replaced, theplunger 205 is sufciently retracted by thrusting against the striker andanvil assembly to maintain the biasing springs 237 under compression bystressing the plunger-engaging legs of the springs out of the inactiveabutment thereof against the upper edge of the plate 238. A forwardlyopening clearance slot or recess 295er in the front edge of the slide orplunger 285 has a retaining pin Zb therethrough for avoiding accidentaldropping out of the plunger during loading.

The loading ngers |76" are pivotally carried by the lower end portion ofthe plunger 295 within the lower end portion of the slot 2|4 and instraddling relation to the feed wheel assembly 2H?. To this end, theloading iingers are pivotally supported at their rear end portions bythe inner end portions of connecting and pintle pins 24|! which not onlysecure the ears |35 of the presser shoe against the outer sides of theplunger 205 but also have their inner ends in supporting pintle relationto the loading finger pivot portions.

A yoke-type torsion spring 24| normally biases the forwardly projectingloading fingers |70 toward the anvil |68. The spring 24| has angularlegs supported upward respective pins 242 which project into appropriatespring clearance space within the slot 2 |4 of the reciprocal plunger atthe sides of the feed wheel assembly 2|ll.

Attachment of the cut-01T and driver member 9|!" and the forming memberei within the recess 92 of the head block is eifected by a headed studscrew 243 the inner end of which extends clear of the proximate forwardwall defining the guideway recess 283 in the head block.

In all forms of the invention the reciprocably slidable striker andanvil assembly including the guide casing, as a unit, provides a readilyremovable head piece not only for loading purposes but also for purposeof inspection of the mechanism and for cleaning out any accumulatedforeign matter such as wool, tobacco, or other inaterial that may belodged therein as a result of carrying the unit in the pocket of a coator the like. Staples of various lengths throughout a substantial rangecan be effectively formed and driven by any of the modifications of theinvention by reason of the novel staple blank strip centering andretaining mechanism. For example, three-eighths inch, ve-sixteenths inchand one-quarter inch staples can be accommodated in the same machine. InView of the powerful direct, two-way rectilinear staple driving thrusteifected by relative movement of the striker and anvil structure and thehead block structure during a cut-off and driving stroke, extremelyshort travel of the cut-olf and driving member is effective. In apractical form, movement of as little as three-thirty-seconds of an inchof the cut-oif and driving member relative to the anvil eifectsseverance of the formed staple from the staple blank strip, and overallmovement of about nine-sixteenths inch of the cut-off and driving memberrelative to the striker portion of the device effects ull driving of thestaple.

By reason of the small number of relatively movable parts in the drivinghead portion of the hammer stapler, highly rugged characteristics can bebuilt into the machine without overweighting the head portion.Furthermore, the various parts can be economically mass produced withsubstantial manufacturing tolerances, and yet by reason of the novelfeed mechanism adjustments and controls, practically foolproof, jam-freelongservice operation of the stapler are assured. By virtue of the smallnumber, of easily assembled,

and fairly simple parts, substantially free from highly criticaldimensional tolerances production costs are minimized and the staplinghammer can be produced and sold at very reasonable cost.

It will be understood, of course, that in the modications of Figs. 20and 23, the handle and magazine sections may be substantially identicaiwith the showing in Fig. 1.

It will be understood that modications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

W'e claim as our invention:

1. In combination in a hammer stapler a manually engageable handlesection, a driving head section, a magazine section between andconnecting said driving head section to the forward end portion of thehandle section, said driving head section having a staple driver at thefron-t thereof and mounted in stationary relation to both the magazineand handle sections, the driver having a lower driving end disposedbelow the lowermost portion of the magazine section, a striker and anvilstructure forming part of the head section and mounted for reciprocalmovement rectilinearly relative to the driver and normally projectingsubstantially below said lowermost portion of the magazine section andbelow the lower end of the driver, and means for feer ing staple meansfrom the magazine section into driving position on said striker andanvil structure under the driving tip of said driver so that when thehammer stapler is wielded to strike a surface with the striker and anvilstructure the latter and said driver will reciprocate for driving of astaple into the surface.

2. In combination in a hammer stapler, a body casing including a handlesection and an enlarged magazine section at the forward end or" thehandle section, said magazine section having means therein forsupporting a coiled strip of sheet metal staple blanks, said means andthe lower portion of the casing at the forward part of the magazinesection defining a feed throat leading forwardly, and a driving headcarried by the forward portion of said casing forwardly of the magazinesection and including staple forming and driving means disposed insubstantially fixed relation to the casing and a striker and anvilstructure mounted reciprocably relative to the staple forming anddriving means for cooperation with the staple forming and driving meanswhen the striker is driven against a surface by wielding of the hammerstapler with a hammer-like blow to afford relative movement between thestriker and anvil structure and the staple forming and driving means todrive a formed staple from the forward terminus of the staple strip fedfrom -the magazine section and form the next succeeding staple blankinto staple form.

3. In combination in a stapling hammer construction, a handle section, adriving head section, and a magazine section intermediate the handle anddriving head sections, said magazine section comprising means defining acavity opening to the right hand side of the magazine section forreceiving a coil of sheet metal staple blanks in continuous strip formwithin the cavity, the opening from the cavity having an openableclosure.

4. In a hammer stapler, means providing a handle section, a driving headsection and an intermediate magazine section; said magazine sectionbeing dimensioned to receive a substan-

